GC048 Column Temperature

High enough temperatures for the sample to pass through the column at a reasonable speed should be used. Nevertheless, it is not necessary the temperature to be higher than the boiling point of the sample. It might seem illogical, but it must be remembered that the column operates at temperatures where the sample is in vapor state and not need to be in the gas state. Thus, in GC, the column temperature must be higher than the “dew point” of the sample, but not higher its boiling point. A good rule of thumb for temperature is that the initial temperature should be low enough that the first peak of interest elutes with a k value of at least 1.0.

High temperatures provoke the retention times to decrease, reducing the analysis time. However, better resolutions are achieved at low temperatures.

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